Global Warming is a reality, and whilst most
of us are focusing on the ecological concerns. Some folk are taking
the opportunity to study the effects first hand...Be afraid...the
Storm Chasers are coming...

by Adam Carter

"There's
no question that greenhouse gasses are there - that they are going
to increase They have a residence time of about 300 years
in the atmosphere, so it's going to take a long time. We really
have to do two things. One is we're going to have to learn to live
with a world that has a different climate than it has today, and
we're going to have to learn how to be more energy efficient."James Baker, Ph.D., Administrator NOAA

Over the past several decades there has
been an active international debate over the cause of global warming.
The question is whether the recently recorded increase in extreme
and unpredictable weather worldwide is due to natural variations in
weather cycles, or whether it results from global warming brought
about by burning fossil fuels.

However over the past few years, the
evidence increasingly points to the fact that these changes are
occurring as a result of man's activities on the planet. According
to Eco-Economy Update, the preliminary global temperature data for
2001 indicates that it was the second warmest year since record
keeping began in 1867. Six of the 10 warmest years ever recorded
were in the 1990s - the other four happened in the 1980s .

There is now a growing consensus amongst
both scientists and politicians that global warming is a man-made
effect - and that it will get worse before the world's climate stabilises.
As far back as 1990, the UN's Intergovernmental Panel On Climate
Change (IPCC) published its first assessment report and announced
that the world's most senior meteorologists agreed that the earth's
climate was warming - with potentially disastrous consequences .

'We can no longer say we are still unsure
whether extreme weather events are caused by global warming or not,'
says Dr Mike Hulme of the Climate Research Unit at East Anglia University
. 'When we look at the Mozambique floods, at the storms that hit France,
at the absence of winters in Britain over the past few years, at the
avalanches in the Alps, we are witnessing events that are now clearly
tainted by human actions.'

The effects
of storms can be catastrophic

The consequences of global warming could become catastrophic and
it is already becoming a serious global economic and human problem.
The escalation in extreme weather conditions over the past two decades
has led to an increase in the frequency and intensity of storm conditions
. Even as 2002 dawned, high temperatures and strong winds were fuelling
intense fires across south-eastern Australia. Flames as high as
20-metres (60-feet) raced through open bush within 16 kilometres
(10 miles) of the centre of Sydney.

Temperatures in the region have soared to over
38 degrees Celsius (100 degrees Fahrenheit) and up to 20,000 fire
fighters - mostly volunteers - battled more than 100 blazes that
overcame firebreaks and containment lines across New South Wales
.

The cause of these fires was a summer
drought in Australia - as in other parts of the world - emergency
rescue crews, meteorologists, scientists and storm chasers followed
quickly onto the scene.

An Introduction to Storm Chasing

In a whirl with the Storm Chasers

In this midst of all this ecological
upheaval are the Storm Chasers who follow at the heels of climactic
change. Storm chasing is the observation or infiltration of any
kind of storm system for scientific research, media reporting (television
and radio), personal interest (such as photography), or even for
recreational purposes.

Anyone who can drive a car, has a thorough
knowledge of the type of storm likely to be encountered and understands
the principles of storm chasing can be involved. You do not need
a special license or training to do it.

If the chaser understands what they
are doing and is aware of what they are dealing with, then storm
chasing is not considered dangerous - although storms do deserve
respect. Alarmingly, it is usually unsuspecting people who become
the victims of storms, not the people who chase them.

Conditions will vary according to the
type of storm experienced and the severity of the event, but you
can generally expect high winds, heavy rain with the possibility
of flooding, very large hailstones, lightning and poor or zero visibility.

The minimum equipment required for storm chasing is protective weather
clothing and a means of transport - namely a vehicle or an aircraft.
For obvious reasons, aircraft tend to be used for professional storm
research. There are several different kinds of chasing activity
which can be broadly categorised according to the kind of storm
system being tracked.

Satellite image
showing wildfires in Mexico due to a long draught

Storm chasers define several different
types of chasing activity. In practice, any type of storm or weather
anomaly can be followed, tracked, and observed and different approaches
can be taken.

Storms can be directly penetrated or
'core punched'. Core punching is when the chaser passes through
the centre of the storm.

For hurricane research, this could
be important but is potentially dangerous. This technique, however,
is too dangerous with a tornado. Storms can also be observed indirectly,
where the chaser passes close to the storm centre, but not actually
through it. This method is best for tornado observation. The method
to choose depends on thorough knowledge of the storm involved, safety
constraints, the type and speed of your vehicle, and most of all,
the type and nature of the storm involved.

Examples of Types
of Storms encountered by Storm Chasers

Extra-tropical Cyclones

These are very large-scale systems
and often only sections of the system are chased at any one time.
The cold front associated with these storms is studied for thunderstorm
and tornado development, whilst the backside of winter storms are
chased for snow reports. The chase usually involves a long drive
to the region of the storm and many hours will be spent waiting,
so patience is a virtue, a trait that all storm chasers need to
develop.

Tropical Cyclones

Although smaller than their extra-tropical
cousins, these tropical cyclones are also large scale. This category
includes both tropical storms and hurricanes - which are systems
associated with extremely dangerous winds and high rainfall. The
core of these systems can be penetrated directly as long as the
winds and rain do not present an unacceptable danger to the chaser.

Chasers have driven their vehicles into and out of the eye of hurricanes,
but reliable vehicles are essential in these circumstances. Strong
hurricanes are not usually penetrated directly by land and a chaser
or chase team will usually position themselves in the path of the
storm and wait for it to come past. Under these conditions, a vehicle
could be anchored to protect against extreme winds. Storm surges
and flooding can also cause major problems in low-lying areas.

Thunderstorms

Storm chasers
report hailstones up to a diameter of 15 centimetres

These are small-scale convective storms
and can be directly penetrated, indirectly penetrated or externally
observed. Direct penetration or 'core punching' can be dangerous
with thunderstorms, as the chaser has to cope with flooding, slippery
roads and sometimes zero visibility - at the very least.

In more severe storms, you can also
encounter strong winds, lightning and large hail. Since thunderstorms
occasionally produce tornadoes, the threat to a core-punching chaser
can be even more serious. Even though a chaser does not go through
the main core, this approach is still potentially dangerous due
to strong winds, lightning and heavy precipitation.

Tornados

Wind directions
around a typical tornado

These are the smallest scale rotary storms - but also the most violent.
They contain huge amounts of kinetic energy concentrated in a very
small area. These storms should always be observed externally from
a safe distance. They are usually observed on the backside (upwind)
side of a very organised thunderstorm, such as a super-cell.

This 'safe' position should have a
clear view of the tornado-producing part of the storm, as well as
good visibility. In the northern hemisphere, this is usually 2-3
kilometres southeast of a storm moving towards the northeast. This
is also a safe place because you stay out of the tornadoes path.
If the thunderstorm is directly penetrated and the chaser emerges
out of the core into the backside of the storm, there is the possibility
of finding a tornado directly in front of the vehicle!

Conclusion

It is clear that a diverse range of
people from amateurs to professionals operate in extreme weather
conditions, and that as Global Warming accelerates there will be
an increasing need for Storm Chasers that follow at the back of
storms to understand how they operate. Global warming may be a reality,
but so are the chasers; and where the weather goes they will follow.